Abstract
The work discusses the mechanisms operating within the climate system leading to variability and changes in the atmospheric climate over Europe. The first part discusses the operation of the main factor regulating the variability of atmospheric circulation, which is the North Atlantic thermohaline circulation (NA THC). The variability of NA THC, through its influence on the shaping of the mid-tropospheric circulation and the distribution of geopotential heights, determines the variability of the lower circulation, and thus the variability of climatic elements over Poland and Europe. The analysis showed that the variability of NA THC largely explains the variability of sunshine duration, air temperature and relative humidity, but does not satisfactorily explain the variability of other climatic elements.